Dam.



N0. 8%,042. PATENTE'D JAN. 1 1907.

W. L. CHURCH.

DAM. AIPLIUATIOH FILED MAR. 28. 1906- PATENTED JAN. 1; 1907.

UNlTED STATES .PAiENT C FFIGEQ WILLIAM LEE CHURCH, OF NEWTON, MASSACHUSETTS.

* DAM.

Specification of Letters Patent.

Patented Jan. 1, 1987.

Application filed March 28, 1906. Serial No. 308.426.

. (This invention relates to a darn formed to inclose or nrotect a space between the upstream and downstream sides of the dam, said space being utilized asa ower-station by installing therein power-utilizing means, such as a turbine and its accessories, and a conduit ada ted to shpply water to the turbine from t e upstream side and to discharge the tail-Water from the turbine in the lower portion of the protected space. In a power-staticn of this character it is very desirable to maintain the tail-water at the discharge end of the conduit at a minimum. level to the end that the wheel-dischargein the draft-tube portion of said conduit may have a maximum fall or head and its maximum efiiciency may be realized. When the backwater level at the downstream side of the dam is relatively high in consequence of high Water the stream or river or from any other cause, the tail-Waterwithin the darn, it allowed to stand at the same level,will correspondingly reduce the head of the wheeldischarge through the drafttube.

My invention hasfor its object to cause the energy of the overfall or Waste water flowing over the apron or spillway of the dam to effect the removal of the tail-water from the interior of the darn, and thereby maintain a relatively low tail-water level within the dam irrespective of the height of backwater below the dam.

To this end the invention consists in the improvements which I will now proceed to describe and claim.

Of the accompanying drawings, forming a part of this specification, Figure 1 represents a transverse section of a darn embodying my invention. Fig. 2 represents a fragmentary sectional-view showing a modification. Fig. 3 represents a horizontal section on line 3 3 cl Fig. 2. 3 y

The same-reference characters indicate the same parts in all the figures.

In the embodiment of my invention here shown for purposes of illustration the dam is of shell form and of reinforced concrete construction. It comprises a deck 12, an" apron 13, and a crest ldguniting the deck and apron,

In said space may be installed a turbine the casing of which is shown at 15, the shaft 16 of the turbine being .connectedwith a dynamo or other power-utilizing means.

18 represents a feed-pipe, the intaire'end of which is in the deck 12, said ipe extending downwardly to the wheel-casing. l9 represents a drafttube. extending downwardly from the Wheel-casing and discharging into the lower portion of the space covered by the darn, the said feed-pipe, casing, and drafttube constituting a conduit taking Water der the desired head from the upstream side bly downstream from the deivering end of the outlet, the movement of the overfail causing a stronglydnduced flow of tail-water outwardly through and from the outlet. The result of this induction is to maintain the tail-Water level within the dam at a lower level than the average levei of the backwater at the downstream side oi the dam. The too of the outlet 20 is referablv lower than the normal. tail-water. .evel wit in the dam, so that'the outlet is usually sealed against the outward passage of are there through above the tail-water, a maximmn discharge of tailevater being thus assured. The overtall preferably impinges upon a sub stantially horizontai hearth 30, which. is a continuation of the bottom of a fiurne Bl, err-- tending outwardly from the interior of the let 20. The hearth 30 should be at about the same height as the bottom oi the outlet 26,

backwater. between the outlet 20 and the hearth. The overfall in its movement across Water on the heartl 30 and induces an outflow of the tail-water by direct contact with it, the combined streams flowing forcibly the Whole covering a space between the 1119- stream and downstream sides of the dam.

and there should be no depression to formi downstream from'the outlet. The outflow:

of the dam, and discharging the tail-water lot is located under the path of-the over'fall, the portion of the apron over the outlet being so inclined. that the overfall 1s nrojected iorcidam-and forming also the bottom of the out the outlet 20 encounters the stream of tail- 1 LIX a dam and recess or opening 22 in the more.

from the dam of tail-water from the interior of the dam may be further increased or augmented by atmospheric pressure. To this end an airdraft flue or passage 21 is preferably provided between the delivering end of the olitlet 20 and the overfall projected from above the outlet. moving cover extending across said flueand tending to continuously exhaust air there from, and thus augment or accelerate the outflow of tail-water by atmospheric pres sure within the dam. The said air-flue is preferably provided by the formation or a lower portion of the apron, the walls of said opening bounding an air-space which is, in efi'ect, an extension of the tail-water outlet located'above the current of tail-water at the discharge end of the outlet.

In Fig. 1 I show the opening 22, provided with a l'm'dge 23, the outer portion 24 of the upper surface of which constitutes an extension of the water-guiding surface of the apron. The inner )ortion 25 of said surface is depressed. an 1 forms the lower side of an extension or enlargement of the air space or flue, the said inner portion and the sheet of overiall over the same forming a ll-shaped air-space from which air is drawn by the movement of the sheet. This construction is intended to increase the exhaustion of'air from the space over the emerging tail-water.

In Fig. 2 I show a recess or opening 22, which is not provided with the shelf 23.

The height of the outlet 20 and its conducting capacity beinglimitcd, I prefer to provide a plurality of said outlets, all connected with a well 32, which receives the tail-water the draittnba Said well elongated in'the direction of the length of. the dafln and communicates through ilumcs with the several outlets, of which there may be two or Provision is thus made for a sulfieiently-rapid discharge of the tail-water to' prevent anobjectionalile aecum ulation thereof within the dam.

I do not claim within the space covered or protected by a having walls which are independent of the dam structure. i

I claim- 1. A power-spsce-inclosing dam having a conduit extending dowiwmrdlyirom the u stream side oi' the dam and discharging in the lower portion of said. space, means at the downstream side of the dam for causing a forcible downstream flow ol' the ovorfall, and means for connecting the tail-water within the dam. with the over-tell-current llowing whereby an outflow of tail Water from the interior oi the dam is induced by the said over-ii l -(:UTT .Ylt.

2. A power-spit rim-losing dam having a conduit extending dovci'lwardly from the upstream side or the darn and discharging in The said overfall forms a constantlythe power-chamber located l l I; l l

the lower portion of said s tail-water outlets in the h ace, a plurality of ownstrearn side of e dam, said outlets being under the path of I the overfall, and means for conducting tailwater from the interior of the dam. to said outlets. T

3. A poWer-space-inclosin conduit extending downwar l stream side of the dam, and the lower portion of said space, and a tailwater outlet in the downstream side of the dam, said outlet being under the path of the dam having a y from the up overfall, whereby the overfall is caused to induce an on said outlet.

4. A power-space-inclosin dam having a conduit extending downwar ly from the 'up- I stream side of the dam, and discharging 1n the lower portion of said space, and a tailwater outlet in the downstream side of the dam, said outlet being under-the ath ofthe overfall, and normally se aled by t e escaping tail-water against the outward passage of air from said space above the tail-water.-

5. A power-spari inclosing dam having an apron or spillway, a conduit extending downwardly from the upstream side of the dam and discharging in the lower portion of the inclosed space, and the lower'portion of the apron, the top of said outlet being connected with the path of the overi'ali by anaindraft passage, which is covered by the sheet of overl all. 6. A power-space-inclosing darn having an apron or spillway, a conduit extending downwardly from the upstream side of the dam and discharging in the lower portion of the incl'osed space, and a tail-we the lower portion of the apron, the said portion being provided with an air-draft passage between the outlet and the path of the overfal 7, A power-spac-e-inclosing dam having an apron or spillway, a conduit extending downwardly from the upstream side of tee dam tward flow of tail-water through incl weed space, and a tail-water outlet 1 the lower portion of the apron, the sat-l por- 'tion" having a recess located above and com Inunicating with the tail-water outlet, and formning an air-draft liuc, the said recess hav inga bridge, the outer portion of which towns a continuati on 01'' the overlall-guiding surface of the apron, while the inner portion forms an extension of the said flue.

S. A power-space-inclosing dam having a condriit extending downwardly from the upstream side of the darn and discharging in the lower portion of said space, a hearth at the downstream side of the dam arranged to deflect the ovcrfall entirely and forcibly d mvnst cam as it leaves the dam, and means for connecting the tail-water within the darn with the overl'all-murent on said hearth.

- 9. A poWcr-spsec-inclosii1g darn having adischarging in a tail-water outlet under" ter outlet under conduit extending downwardly fr0m-the.upconduit and connections between the Well stream side of the dam and discharging in and the said outlets. I 10 the lower portion of said s ace ajplumlity of In testimony whereof I have affixed my tail-water outlets in the ownstream side of signaturein resence of two Witnesses.

the dam, said outlets being unde! the path of I ILLIAM LEE CHURCH; the overfall e, continuous well elongated in Witnesses: the direction of the axis of the dam, and ar- H. L. COBURN,

ranged to receivethe tail-water from said H. 0. WHITE. 

